During radiotherapy it is essential to track the movement of the target area in order to increase the efficiency of the treatment and to reduce the effect of radiation on nearby tissue. Positioning systems have been developed by Micropos Medical AB to track variations using an emitted electromagnetic signal which is received by a plurality of receiving elements, as disclosed in the published international application WO 2005/104976.
In the published international application WO 2007/061351, assigned to Micropos Medical AB, a combined device for dose measurement and tracking positioning is disclosed. Other types of sensors, such as temperature, are also suggested to be implemented together with an electronic identification tag used to verify the patient before performing radio therapy treatment.
A drawback with the prior art devices is that the design is rather complex which results in an expensive or bulky design.